linux/include/uapi
Anton Protopopov f654b258e9 bpf: Pack struct bpf_fib_lookup
[ Upstream commit f917170072 ]

The struct bpf_fib_lookup is supposed to be of size 64. A recent commit
59b418c706 ("bpf: Add a check for struct bpf_fib_lookup size") added
a static assertion to check this property so that future changes to the
structure will not accidentally break this assumption.

As it immediately turned out, on some 32-bit arm systems, when AEABI=n,
the total size of the structure was equal to 68, see [1]. This happened
because the bpf_fib_lookup structure contains a union of two 16-bit
fields:

    union {
            __u16 tot_len;
            __u16 mtu_result;
    };

which was supposed to compile to a 16-bit-aligned 16-bit field. On the
aforementioned setups it was instead both aligned and padded to 32-bits.

Declare this inner union as __attribute__((packed, aligned(2))) such
that it always is of size 2 and is aligned to 16 bits.

  [1] https://lore.kernel.org/all/CA+G9fYtsoP51f-oP_Sp5MOq-Ffv8La2RztNpwvE6+R1VtFiLrw@mail.gmail.com/#t

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Fixes: e1850ea9bd ("bpf: bpf_fib_lookup return MTU value as output when looked up")
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240403123303.1452184-1-aspsk@isovalent.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-16 13:39:18 +02:00
..
asm-generic signal: Deliver SIGTRAP on perf event asynchronously if blocked 2022-06-09 10:22:48 +02:00
drm drm/fourcc: Add packed 10bit YUV 4:2:0 format 2022-12-31 13:14:10 +01:00
linux bpf: Pack struct bpf_fib_lookup 2024-06-16 13:39:18 +02:00
misc habanalabs: fix resetting args in wait for CS IOCTL 2021-09-29 12:18:48 +03:00
mtd
rdma RDMA/mlx5: Don't compare mkey tags in DEVX indirect mkey 2022-10-26 12:35:03 +02:00
scsi scsi: fc: Add EDC ELS definition 2021-08-24 22:56:33 -04:00
sound ASoC: Intel: Skylake: Fix declaration of enum skl_ch_cfg 2023-05-30 13:55:33 +01:00
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